Mortgage credit granting has to be supported by task-oriented instruments (highly interactive support tools that enable cooperative problem solving) because of increasing competition and unfriendly economic circumstances. mocca (mortgage controlling and consulting assistant) provides instruments for decision support, customer consultancy, and management. Most of the underlying models in mocca are innovative in terms of being either completely new or operative for the first time. The implementation of the application is based on a combination of different knowledge-based techniques, such as agent-based processing, generic application building blocks, fuzzy measure, data-driven paradigm, and a two-layer windowing system. mocca (mortgage controlling and consulting assistant) is now being used in the major branch offices of Swiss Bank Corporation (SBC). The development of the application required two person-years.